Montanaanimal Species of Concern
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MONTANA A NIMAL A program of the Natural Resource Information System, Montana State Library SPECIES OF CONCERN JULY 2004 INTRODUCTION This report is produced on an annual basis jointly by the Montana Natural Heritage Program (MTNHP) and Montana Fish Wildlife and Parks (MFWP). Montana Species of Concern are native animals breeding in the state that are considered to be “at risk” due to declining population trends, threats to their habitats, and/or Coeur d’Alene Salamander restricted distribution. (Plethodon idahoensis) Illustration by John Carlson Also included in this report are Potential Species of Concern -- animals for which current, often limited, information suggests potential vulnerability or for which HERITAGE PROGRAM RANKS additional data are needed before an accurate status assessment can be made. Many of these species have The international network of Natural Heritage Programs ranks reflecting the uncertainty of their status, and we employs a standardized ranking system to denote global hope that highlighting them as Potential Species of and state status. Each species is given a global (G) rank, Concern will encourage biologists to conduct surveys and denoting rangewide status, and a state (S) rank for its submit new data. The category “Species on Review” status in Montana. Status ranks range from 1 (greatest included in the 2003 report has been merged into Potential concern) to 5 (least concern). Global ranks are assigned by Species of Concern. scientists at NatureServe (the international affiliate organi- Status determinations are made by MTNHP and zation for the heritage network) in consultation with MFWP biologists in consultation with representatives of biologists in the natural heritage programs and other the Montana Chapter of the Wildlife Society, the Montana taxonomic experts. State ranks are determined jointly by Chapter of the American Fisheries Society and other MTNHP and MFWP biologists, in consultation with other experts. The process for evaluating and assigning status state experts. designations uses the Natural Heritage Program ranking The combination of global and state ranks helps system, described below, which forms the basis for describe the proportion of a species’ range and/or total identifying Montana Species of Concern. population occurring in Montana. For instance, a rank of This report identifies 119 vertebrate and 58 inverte- G3 S3 indicates that Montana comprises most or a very brate Species of Concern. Another 37 vertebrates and 50 significant portion of an animal’s total population. In invertebrates are identified as Potential Species of contrast, an animal ranked G5 S1 often occurs in Montana Concern. See the “Box Scores” below for totals by animal at the periphery of its much larger range; thus, the state group. Thirteen species included in the 2003 report have supports a relatively small portion of its total population. been dropped from consideration (see page 11). BOX SCORES Species of Concern Potential Species of Concern Amphibians ...........................................................5 Amphibians ...........................................................0 Birds ..................................................................... 60 Birds ..................................................................... 18 Fish ...................................................................... 18 Fish ...................................................................... 10 Mammals .............................................................. 27 Mammals .............................................................. 9 Reptiles ................................................................ 9 Reptiles ................................................................ 0 Invertebrates - Insects ......................................... 29 Invertebrates - Insects ......................................... 48 Invertebrates - Mollusks ...................................... 22 Invertebrates - Mollusks ...................................... 2 Invertebrates - Other ............................................ 7 Invertebrates - Other ............................................ 0 © 2004 Montana Natural Heritage Program 1 What’s on the Lists has not yet been applied to invertebrates, so the ranks Montana Species of Concern are defined as vertebrate presented in this report reflect the traditional ranking animals with a state rank of S1, S2, or S3. Vertebrate approach. species with a rank indicating uncertainty (SU) or a “range rank” extending below the S3 cutoff (e.g., S3S4) are Definitions of Ranks used in this Report considered Potential Species of Concern. Because documentation for invertebrates is typically G1 / S1 At high risk because of extremely limited and/or far less than for vertebrates, only those ranked S1 or S2 are rapidly declining numbers, range, and/or habitat, included as Species of Concern. Invertebrates ranked S3 making it highly vulnerable to global extinction or are included only if they are also considered globally extirpation in the state. vulnerable (G3 or higher) or if experts agree their occurrence in Montana has been adequately documented. G2 / S2 At risk because of very limited and/or declining All other invertebrates ranked S3 are treated as Potential numbers, range, and/or habitat, making it Species of Concern. Also included as Potential Species of vulnerable to global extinction or extirpation in the Concern are globally common (G4 or G5) invertebrates with state. a range rank extending below the S2 cutoff cited above (e.g., S2S4). Invertebrates ranked as SU have been G3 / S3 Potentially at risk because of limited and/or dropped from Potential Concern. declining numbers, range, and/or habitat, even though it may be abundant in some areas. How Species are Ranked This year, we began implementing a more rigorous G4 / S4 Uncommon but not rare (although it may be rare in methodology with more consistent and quantifiable criteria parts of its range), and usually widespread. to assign status ranks. The goal is to improve the accuracy Apparently not vulnerable in most of its range, but of ranks and better document the basis for each rank. possibly cause for long-term concern. Having a rigorous and well-documented ranking procedure is especially important to MFWP, which is using status G5 / S5 Common, widespread, and abundant (although it ranks to help set priorities for the state’s Comprehensive may be rare in parts of its range). Not vulnerable in Fish and Wildlife Plan. most of its range. This new approach to assessing species’ status is based on methods developed by NatureServe (Master et al. GU / SU Currently unrankable due to lack of information or 2003). In December 2003, a group of staff and other experts due to substantially conflicting information about met to review the proposed process, tested it on a variety status or trends. of taxa, and endorsed its use in the 2004 status review. Staff then contacted Montana experts for each animal GH / SH Historically occurred; may be rediscovered. group and asked them to rank species according to six separate criteria. These criteria included population size, GX / SX Believed to be extinct; historical records only. area of occupancy in Montana, short and long-term trends, threats, inherent vulnerability, and specificity to Other codes and rank modifiers: environment. Based on this expert input, a preliminary rank B / N State rank modifiers indicating the breeding status was calculated, which then was reviewed with key experts. for a migratory species; B = Breeding, N = Non- It is important to note that while the ranking process breeding. has changed, the definitions and the fundamental criteria remain the same. The principle difference is that criteria are HYB A global rank denoting a hybrid. now being applied in a more rigorous and consistent manner. Detailed documentation of the criteria and M A state rank modifier indicating migratory assessment process are available on the MTNHP website stopover status for a species. at mtnhp.org/animals/index.html. This status assessment process was completed for all Q A global rank modifier indicating that there are of Montana’s amphibian, reptile and mammal species. Due taxonomic questions or problems. to the large number of bird species in the state, only those already on the 2003 Species of Concern list were evaluated T Denotes the rank for a subspecific taxon to date; the remaining bird species will be assessed in (subspecies or population); appended to the future revisions. Updated ranks for fish are not included in global rank for the full species. The S Rank this report, to allow the Montana Chapter of the American following applies to the subspecific taxon. Fisheries Society additional time for review; they will be reported in the 2005 update. The new ranking methodology ? Denotes inexactness or uncertainty. © 2004 Montana Natural Heritage Program 2 HOW TO READ THE LISTS ADDITIONAL INFORMATION Species are listed alphabetically by common name Our internet-based Field Guide to Montana’s Animals, within major groups, which are organized alphabetically completed in 2003, provides information on over 600 under Vertebrates and Invertebrates. Species with names vertebrate species, including Species of Concern and bolded and underlined are new additions to the Species of Potential Species of Concern. The Field Guide offers a broad Concern or Potential Species of Concern list. (Those range of information, including species identification, range, downgraded from Concern to Potential